I upgrading my old boat and I am installing a new 24 volt Fortrex 80lbs trolling motor using the marinco lock plug and Marinco Trolling Motor Receptacle, i have 2 heavy black wires and 2 red wires going back to my battery's. My question is do i need a jumper on my battery's going to Pos on one battery and neg to the other. or just hook straight up the 2 black one on each battery and the same using the Pos.

Thank your help and info

you need the jumper then use both red to pos on one battery and both black to neg on other battery. that gives 24v

black to neg/red pos like you described is only 12v

Ok thank you for your help, just so i understand i need a jumper going to neg battery 1 battery and to the pos to battery 2. and then hook the black and red wires to each battery?

Those plugs are set up for 12/24 volt use. A lot of the older trolling motors were 12/24 volt. If you check voltage you will have both in the plug a ground, a 12v and a 24v terminal. That’s why you have 2 black and two reds. Both battery are brought to the front. The plug has a jumper in it that puts them in series. Creating the 24v system. I kept mine like that. I just wired my new Ultrex to the 24v terminals and I’m set. You can read up on it on the web. No jumping at the battery needed.

Thank you Coolarrow i just trying to make sure i am doing this right with out burning something up.

ok so you are saying no jumper needed. Just hook to Po's wires to Po's post and neg to the neg post's and your done?

Like I said on the plug there will be a 12v and a 24v position. You will only wire your new motor up to the 24v one. Red on positive and black on negative. Do you have a volt meter to check?

double check to make sure your plug is a 12/24, if it is go with coolarrows post, if not use my post.

the female plug on a 12/24 system has the conversion circuit in it, not the male end. if just plugging in to a 3 prong plug then use my post, if the female side has 12/24 switch in it then use coolarrows.

just going off how my 82 champion 184 was set up, had to switch the bow plug between voltage with a toggle switch.

On the champ I had (1994), one leg carried 24v and the other leg only had 12v. Go buy yourself a $15 multimeter and find out what you really have and don’t burn something up.

what boat is this going on and can you post a picture of the bow plug?

if you are wiring from the batteries to the bow plug direct (no 12v) then use my post above, you will have to have the jumper to get 24v.

ONLY if you have a bow plug that is labeled 12/24 with the switch to change do you use cool arrows first set up.


were it my boat, I would use the direct 24v, both reds to one leg of the plug, both blacks to the other leg of the plug, jump batteries from pos-neg and use empty pos/neg to connect to 60a manual reset breaker then I would use 6 or 4 ga. to run from the breaker to the front with same ga. as battery connections to breaker.

6ga will work but will get hot if you have to make a long run due to big engine failing. I just went thru this on fork, south side of 515w bridge to williams creek. rewiring mine next weekend to 4 ga. has single strand 6ga. now. and I blew the breaker once due to overheating.


and for sure get a multimeter and use it to verify voltage at plug, 12v will end up really shortening the life of a 24v motor

100% of what Hop said. I was not aware there was a three prong twist lock plug. Everyone I have ever seen was a 4 prong. Check voltage before you hook up anything!

Thanks Guys for you Help , My Boat is a 1996 Express

The male and female plugs i am using is the marinco lock plug and marinco Trolling Motor Receptacle 4 prong's, is say in the front of the female receptacle 12-24. I have no switch to change it back in fort from 12 to 24 on the boat itself. Ok now on the old motor guide that I took off it did have a toggle switch on the trolling motor for 12/24. So now the new Fortrex is just a straight 24 volt. On back of the female receptacle i got 2 black wires and 2 red wires hooked up per the instructions that the receptacle came with going back to the battery's at the back of the boat i have a in line breaker 50amp on each pos red wire. so that is where I am at now.

Take the cover off of the male side of the plug to install it. There will be 4 holes w/ screws to secure the wires. They should be marked as to where they go. Your new trolling motor wire has a red and black wire. Black goes to - and red goes to 24v +. I always confirm that I have the proper voltage and polarity before hooking it up. Your volt meter will read 24v+ if it’s right. If it says 24v- the red and black are swapped.

Yes that is the same video I watched how to do my male plug and also the next one same guy on how to hook up the female receptacle. so in the back of the boat I just hook up the black wires to the neg on each battery and red to pos on each battery with a jumper going to pos post on 1 battery to the neg post to the other battery. Is this right?

The marineco 4 wire twist lock 12/24v plug has a internal jumper that creates the series connection required. No jumper is needed at the battery. Man you might just want to run by a marine place and get a little help. If I was closer I would help you. You sure don’t want to burn something up. I know there is a lot of info out there. Lots of drawings. That plug is an awesome plug but miss understood. It was designed for charging batteries. When you unplug the motor plug it opens up the 24v tie so the two 12v batteries charge separately.